Originally Posted By: cueball89
Originally Posted By: dparm
Curious why you moved up to 0w40. The results don't look much better, if at all, versus the 0w20.
I think you could dial it back to something lighter, assuming it maintains oil pressure under the hard cornering of autocross. If you are concerned about the wear from WOT at autocross, maybe get one of the more stout 0w20s like Motul 300V or Red Line.
I was getting oil temperatures of 240f-250f while autocrossing, the corresponding oil pressure at idle was around 3-5 psi. I can't add an oil cooler to the car in the class that I run so I bumped up the oil viscosity. The Japanese service manual for this engine does spec up to 5w-40 for severe use. If I had a readily available non resource conserving 0w-30 oil at ~ $5 a quart I'd have run that. A light 0w-40 seems to be doing fine.
On a road trip to Lincoln Nebraska at 75 mph I got 30-33mpg and at 80mph+ I was getting around 28mpg with all of my autocross gear. The heavier oil doesn't seem to have affected mileage much.
240-250 degrees isn't really that bad, I get hotter temps than that on the track with no ill-effects. The 0w40 is certainly working fine, I just think you could probably run something thinner.